WASHINGTON (AP) — The Justice Department on Monday announced a new code of professional responsibility for its forensic science laboratories and also cautioned its examiners and prosecutors to use restraint in discussing the strength of their findings.
The announcement, in a memo from Attorney General Loretta Lynch, follows scrutiny of the department's laboratory protocols and procedures.
Last year, the Justice Department revealed that experts had overstated the strength of their evidence dating back decades in many cases that involved microscopic hair analysis. In February, department officials announced a review of forensic sciences practiced by the FBI to ensure that experts are not overstating their findings and that other scientific disciplines have not been tainted by flawed testimony.
The new memo encourages restraint among forensic scientists, including asking forensic examiners and prosecutors to no longer use the phrase "reasonable scientific certainty" in their reports or testimony.
"Today's announcement marks yet another step forward in the department's efforts to strengthen the practice of forensic science in our nation's laboratories and courtrooms," Deputy Attorney General Sally Yates said in a statement. "We are continually looking at ways to ensure that forensic evidence is collected, analyzed and presented in a responsible and scientifically rigorous manner."
In announcing new policies, the Justice Department was acting on recommendations from the National Commission of Forensic Science, which advises the attorney general on the use of scientific evidence in the criminal justice process.
The memo also mandates a series of requirements, including that forensic examiners avoid participating in cases in which there is a conflict of interest, handle evidentiary materials in a way that prevents tampering and that they make sure that their conclusions and opinions are supported by sufficient data.